US2739942A - Detergent compositions - Google Patents

Description

United States Patent DETERGENT COMPOSITIONS Eddy W. Eckey, Wyoming, Ohio, assignor to The Procter and Gamble Company, Ivorydale, Ohio, a corporation of Ohio No Drawing. Application June 25, 1951, Serial No. 233,497

Claims. (Cl. 252'-132) This invention relates to new detergent compositions, and more particularly concerns new detergent compositions suitable for use in either soft or hard water, both in the household where mildness is desirable and in the laundry where heavy-duty performance is required, such compositions comprising organic detergents and watersoluble salts of phytic acid.

An object of the present invention isto provide generalpurpose household detergent compositions having superior performance in hard water.

Another object is to provide detergent compositions that will suds and clean in hard water as well as or better than heavy-duty or other detergent compositions of the prior art.

A further object is to provide heavy-duty detergent compositions which show a greatly reduced tendency or show no tendency to produce precipitates or insoluble curd such as are obtained with many detergents either during washing or rinsing in hard water.

A still further object is to provide a detergent composition which combines the properties of heavy-duty performance and resistance to the formation of curd in hard water with the property of unusual mildness toward the skin.

Other objects and advantages of the invention will be apparent during the course of the following description.

Numerous inorganic salts have been used in combination with both soap and synthetic detergents, such as carbonates, hydroxides, silicates, borates, sulfates, pyrophosphates, and orthophosphates. However, detergent compositions containing such salts have, in general, been found to possess one or more characteristics that are undesirable to the housewife, such as high alkalinity, detrimental action on skin and fabrics, fabric-color fading and poor detergency. In more recent years, polyphosphates have been used in detergent compositions and, while such compositions are relatively mild, they all have a tendency to revert to the orthophosphate form, particularly in water solution. Of the polyphosphates, the triphosphates undoubtedly have been the most satisfactorybuilding agents used in detergent compositions of the prior art, but due to their tendency to revert in the presence of water (even though it be much less than that of the 'polyphosphates that-have a higher P205 content), their use has generally een limited to dried or crystallized products.

In direct contrast such disadvantages of detergent compositions of the prior art are eliminated in the compositions of my invention, wherein water-soluble phytates are used in combination with organic detergents. These new compositions-possess excellent detergent and sudsing properties equa'l to and in manyinstances far'superior tothose of compositions wherein like amounts of 'triphosphates and organic detergents are used, and these properties are obtained without resorting to very high alkaline conditions that are detrimental to fabrics, colors and the skin. Because of the stability of the phytates these compositions can be used, if desired, in boiling water without undergoing formation of hydrolysis products that have'poorer I ly reducing the cost of packaging and marketing the liquid composition.

These phytate organic-detergent combinations exhibit excellent detergent and calcium sequestering properties in hard water; and the phytate-synthetic detergent'compositions in particular show a remarkably reduced tendency to form the insoluble precipitates experienced during washing' or rinsing when employing many of the detergent compositions of the prior art in hard, water. In this specification and in the appended claims, the term, organic detergent means any representative member or mixture of members of the group consisting of the following types of detergents: (1) ordinary water-soluble soaps, containing from 8 to 18 carbon atoms in the molecule, such as the alkali metal, ammonium and substituted ammonium salts of the higher fatty acids that may be obtained from naturally occurring plant or animal esters or that may be produced synthetically (e. g. by oxidation of petroleum or by hydrogenation of carbon monoxide by the Fischer-Tropsch process), resin acids and/ or naphthenic acids; (2) synthetic organic detergents, characterized by their high solubility in water, their resistance to precipitation by the constituents of hard water, and their surface active and effective detergent properties, which include: (a) anionic synthetic detergents (excluding true soaps), such as water-soluble salts of sulfuric reaction products or alkyl and substituted alkyl compounds containing from 8 to 18 carbon atoms in the alkyl group, (some examples of such anionic synthetic detergents being alkyl sulfates, alkyl benzene sulfonates, sulfoethyl oleate, alkyl sulfoacetates, monoglyceride sulfonates, monoglyceride sulfates, alkyl glyceryl ether sulfonates, sulfoethyl- N-methyl oleic amides, alkyl sulfonates, etc.) (b) nonionic synthetic detergents, such as the reaction products of higher alcohols and higher fatty acids with considerable amounts of alkylene oxides. In this latter class the alcohols and acids usually contain from 8 to 18 carbon atoms, but may in some cases contain as little as 5 carbon atoms.

Numerous examples of such synthetic organic detergents are mentioned in Linds U. '8. Patent 2,396,278.

By the term phytates I mean water-soluble salts, such as alkali metal, ammonium and substituted ammonium salts, of phytic acid, which acid is generally accepted to consist essentially of inosite hexaphosphoric acid and probably small quantities of other less highly phosphorylated inositol derivatives. Phytic acid salts are found in corn, soybeans, and in other grains and plants, from which they may be obtained by acid water extraction, as for example in the steeping of corn, phytic acid salts are found in the steeping liquors.

In the term building, I refer to that property of certain materials to enhance the sudsing and/or detergent characteristics of organic detergents when these mate rials are employed with the detergent in cleaning opera tions in Water solution. The relative building action of a builder or building agent may vary somewhat with the detergent used, as for example, some non-ionic detergents upon being built with the phytates will show a marked increase in both sudsing and detergency, some will show a marked increase in sudsing but not in detergency and others will show a marked increase in detergency but not in sudsing; Likewise the optimum amount of builder will vary in view of all the conditions that have to be met in economy, sudsing and detergent performance, mildness, etc.

Whereas phytates are recommended for use in heavyoneness Solutions in water having a hardness -:of 7 grams per gallon were prepared containing 0.35% ofthese compositions; and the sudsing and detergent properties of each composition were measured by washing 5 consecutive loads .of cotton cloths in the same manner asusedin'Example 3.

Comparison of the soiled cloths after washing showed that those washed with compositions B, .C and D were all cleaner than those washed with composition A, as is illustrated in Table 111 wherein the numerical values show the whiteness of the washed cloths as measured by a photovolt photoelectric reflection meter, the higher values representing greater cloth whiteness and accordingly greater detergent action of the washing solutions. Each value shown represents the average of duplicate runs of five soiled cloths for each washing.

TABLE III Detergency comparison Composition A B P/SD Ratio /1 0.5/1 2/1 5/1 Cloth Whiteness 5th Load 1 PISD=ratio of sodium phytate/synthetic detergent.

Attention is called to the fact that the presence of phytate produced an exceptionally great building action as indicated by the whiteness of the washed cloths in the first loads. Attention is also called to the large increase in detergent capacity as the phytate-synthetic detergent ratio was'increased from 0.5/1 to 2.1. That is, the capacity of the 0.5/1 composition for heavy duty washing falls off rapidly after washing the first load whereas the capacity or" the higher ratio compositions continues through an increased number of washings.

It is of further interest that the phytates are unusual in that they produce a much greater building action at low ratios than do other builders. .Thus at a ratio of about 08/1 the detergent capacity isalmost equal to that of the compositions having ratios of 1.5/1 and 2/ 1. In consequence from the standpoint of obtaining maximum performance with minimum phytate usage, the range of ratios of 08/1 to 2/1 is thus a preferred range particularly during periods when the cost of the phytate exceeds the cost of the detergent. The superior building value of the phytates is illustrated in particular by comparisons of detergent compositions containing 1.2 parts of sodium phytate and 1 part of alkyl benzene sulfonates or alkyl sulfates or mixtures thereof with compositions containing 3 parts of sodium triphosphate and 1 part of the same detergents. In each case the phytate compositions showed the highest detergent properties. A further comparison showed that compositions in which the triphosphate/synthetic detergent ratio was reduced to 1.5/ 1 exhibited much poorer detergcncy than the above phytate and triphosphate compositions.

Attention is called to the fact that as with the soaps the phytate building action for synthetic detergents is not limited to hard waters. The following example illustrates its building action in water containing no hardness.

Example 5.A detergent composition consisting of 2 parts of sodium salts of sulfated fatty alcohols obtained by the reduction of the mixed fatty acids derived from coconut oil, 1 part of sodium phytate and 7 parts of sodium sulfate was compared in a launderometer with a composition consisting of 2 parts of the same sodium alcohol sulfates and 8 parts of sodium sulfate. The comparisons were made in water having zero grains of hard- 6 .ness in :the manner ldescribed in Example 2, the follow ing-results beingiobtainedat' concentrations of 0,10% and 10.20% -of the detergent compositions.

The sodium sulfate observed in some ofthe above formulae. is frequently used in detergent compositions and is often a'b'yproductofsynthetic detergent manufacture. Detergency tests performed on similar phytate-containing formulae in which the sodium sulfate is omitted give substantially the same results as are obtainedwhen the sulfatetis present. i

The marked buildingaction of the phytates at low ratios is ofparticular value in the preparation of liquid detergent compositions; One of the problems of the detergent industry has been to formulate concentrated'homogeneous liquid detergents for heavyduty laundry work. The,phytates are particularly suited for such compositions because in addition .to their remarkable 'building power at low ratios.they-also have a very high solubility in water. .The latter pointissillustrated by comparison of the solubility of sodium phytate with the solubilities of various other builders.

Maximum solubility at Builder 25-C. oftho anhydrous salt Percent Sodium tri'phosphate.. 13 Sodium pyrophosphate 6 Sodium ortho'phospha't 12 Sodium tetraborate. 5 Sodium phytate; 41

Aqueous solutions of the water-soluble phytates and water-soluble detergents can be prepared in unusually high concentrations ranging as high as'about 60% total dissolved matter at room temperature. Typical examples of such are (1) an aqueous solution containing 13% "of sodium phytate and about 45% of a mixture of triethanol amine sulfates of alcohols derived from the sodiurnreduc- -t'ion of coconut oil, (2) an aqueous solution of 25% of sodium phytate and 20% sodium alkyl sulfate, (3) an aqueous solution of 30% potassium phytate and 20% of potassium soaps prepared from coconut oil, and (4) a similar .solution-of20% potassium phytate and 30% of the same potassium soap.

In preparing such solutions obviously care should be exercised to avoid the addition of materials that will promote the formation of highly insoluble compounds, precipitation by common-ion effects, etc. It is preferable to select the materials so that the total cencentration of detergent plus phytate is usually not less thanl0%. At lower concentrations the size of the container required to hold a normally salable amount of detergent would be somewhat cumbersome for general household usage.

While the above discussion has been directed primarily 'to homogeneous solutions, I wish also to include in the term solutions, as used in connection with these compositions, liquid mixtures of phytates and detergents such as gels, substantially stable suspensions and emulsions, and other varieties of dispersions of solid and liquid in liquids. In'some cases the heterogeneous dispersions may be more desirable than the clear aqueous solutions. The alkyl benzene sulfonates, for example, can be used to good advantage with the phytates preparing stable emulsions.

phytates. For example, ratios as high aslS partsot phytate to 1 part of soap have been used with excellent resvlts- A Although the detergent buildingaction' of phytates'has been primarily stressed thus far, phytates also show a marked suds building action. Inflalmost every instance phytate built the suds in the above" described compositions except, for example, in the case of some of the non-ionic detergents. In waters of low hardness very small amounts of phytates can improve thesudsing of soaps. Synthetic detergents show'improved suds ing at ratios as low as about 0.2/1 and suds continue to be builtwith both synthetic detergents and soaps as theratio is'increased to /1 and above. n

In the preparation of detergent compositions "wherein evengreater sudsing action is desired than is obtained with the above compositions, other building agents .can also be included particularly agents such as high molecular weight fatty alcohols, fatty, acid 'nitriles, and fatty acid amides, examples of such being lauryl alcohol, myristic nitrile, myristic amide and lauryl ethanol amide.

Despite the fact that most of the phytate built'detergent compositions described above show such excellent detergent properties that they are considered to be heavyduty detergents, they are also characterized by mildness toward fabrics and skin.

The detergent compositions described above are not limited to the particular detergents described. The various soaps and synthetic detergents described above in the definition of these materials can be substituted for detergents of the same type that were used'in the above examples and illustrations with substantially the same results.

It is to be understood that the foregoing more particularly described examples are to be considered as illustrative of some preferred compositions, and that such changes andmodifications therein are contemplated as would normally occur to those skilled in the art to which the invention relates.

The detergent compositions can be prepared withindividual phytates and detergents or with mixtures of the various water-soluble organic detergents and phytates. Such compositions may be prepared in any of .the common physical variatoins such as liquid, bar, flake, thread, powdered or spray-dried forms.

While the cleansing agent of the compositions of the present invention comprises'essentially organic detergents :and phytates' as herein described, it will be appreciated that the incorporation in the mixture of additional compatible ingredients commonly used with detergents such as perfumes, inorganic and organic builders, various inorganic salts, etc., is contemplated as part of the instant invention. I

Havmg'thus described my invention, what I claim and desire to secure by Letters Patent is:

1. A cleansing composition consisting essentially of one part of an organic detergent of the group consisting of water-soluble soaps, non-soap anionic synthetic detergents, non-ionic syntheticdetergents and mixtures thereof, and abuilding amount, in the range of from about onefifth part to about fifteen parts, of a water-soluble phytate, said composition having'a moisture content such that, the

total concentration of the detergent'plus phytate is not less than about 10%.

2. The composition of claim 1 wherein the detergent is an alkyl sulfate containing from 8 to 18 carbon atoms in the alkyl group.

3. The composition of claim 1' wherein the detergent is an alkyl benzene sulfonate containing from 8 to 18 carbon atoms in the alkyl portion thereof.

4. The composition of claim 1 wherein the detergent is a water-soluble soap containing from 8 to 18 carbon atoms.

5. The composition of claim 1 in the form of an aqueous solution containing from about 10% to about of the described ingredients. I

6. A heavy-duty cleansing composition consisting essentially of one part of at least one water-soluble nonsoap anionic synthetic organic detergent, and a building amount, in the range of about 0.8 part toabout 5 parts, of a water-soluble phytate, saidcomposition having a moisture content such that the total concentration of the detergent plus phytate is not less than about 10%.

7. Aheavy-duty cleansing composition consisting essentially of one part of a water-soluble anionic 'organicdetergent, and a building amount, in the range of 0.8 part to 2.0 parts, of a water-soluble phytate, said composition having a moisture content such that the total concentration of the detergent plus phytate is not less than about 8. The composition of claim 7 wherein the detergent is an alkyl benzene sulfonate containing from 8 to' 18 carbon atoms in the alkyl portion thereof.

9. The composition of claim 7-wherein the detergent is an alkyl sulfate containing from 8 to 18 carbon atoms in the alkyl group.

10. An aqueous solution of the composition of claim 7.

wherein the total concentration of the detergent plus phytate is not more than about 60 References Cited in the file of this patent UNITED STATES PATENTS 2,497,062 Artz J Feb. 14, 1950

Claims (1)

1. A CLEANSING COMPOSITION CONSISTING ESSENTIALLY OF ONE PART OF AN ORGANIC DETERGENT OF THE GROUP CONSISTING OF WATER-SOLUBLE SOAPS, NON-SOAP ANIONIC SYNTHETIC DETERGENTS, NON-IONIC SYNTHETIC DETERGENTS, AND MIXTURES THEREOF, AND A BUILDING AMOUNT, IN THE RANGE OF FROM ABOUT ONEFIFTH PART TO ABOUT FIFTEEN PARTS, OF A WATER-SOLUBLE PHYTATE, SAID COMPOSITION HAVING A MOISTURE CONTENT SUCH THAT THE TOTAL CONCENTRATION OF THE DETERGENT PLUS PHYTATE IS NOT LESS THAN ABOUT 10%.